Ignoring configure related scripts

When building idesk with sm_notify support, configure
related files are magically modified. We don't want to
push these files up&down all the time.
Support for singleton applications

A new parameter in the desktop icon files allows
for running single instance applications. Add this flag:

Singleton: true

When the icon is double clicked, and if the
application is running as specified in the "command" parameter,
idesk will refuse to start it again.

TODO: Add SM_notify event so the window manager
can switch focus to the application.
Fixed singleton bug

The singleton feature stopped working
after a logoff/logon transition.
The class member variable used to collect the icon information
needed to go to the base abstract class.
Improve code to detect singleton apps

 o Code moved to a centrla function
 o Search is done using the command line first, then the caption
 o Some apps launch a program and the commandline disappears, caption is inconsistent (video - Make Youtube). We should put this in common.
Fixed icon flickering effect and random icons on top of apps

 o Added debug messages to xevents loop
 o Spotted Expose events, removed redrawing. Most likely our Xserver
   has backing store enabled.
 o Added comments on source code.
Added support for "AppID"

For singleton-like apps, the appid makes it possible to provide
a regular expression which will be used by "pgrep" to decide if
the app is running or not.
Merge pull request #2 from KanoComputing/flickering

Fix idesk flickering effect